Syntheses, Structures and Properties of Two New Coordination Polymers with Flexible Ligands as Linkers

Two new coordination polymers, [ZnL1](n) (1, H(2)L1 = 5-(4-pyridyl)-methoxyl isophthalic acid) and [Ni(L2)(2)(H2O)(4)](n) (2, HL2 = 4-(pyridin-4-ylmethoxy)benzolic acid), have been synthesized and characterized by elemental analysis, PXRD, IR spectra, and single-crystal X-ray diffraction. Compound 1 has a three-dimensional framework constructed by 6-bridged L1(2-) anions connecting the Zn-2(O2C)(4) paddlewheel-like units. Compound 2 contains a mononuclear molecular unit, and the central nickel atom adopts a slightly distorted octahedral geometry by two nitrogen atoms from different L2(-) ligands and four oxygen atoms from water molecules. These molecular units link each other via four types of O-H center dot center dot center dot O hydrogen bonds to form an extended three-dimensional (3D) supramolecular network. The thermal and photoluminescent properties of 1 and 2 have also been investigated.